1. Field of the Invention
The present invention relates to a latex composition suitably usable for the production of water-proofing materials, cement mixing materials, oil extended rubbers, especially road-paving materials and a process for producing the same, and an asphalt composition and a cationic asphalt emulsion using the same.
2. Description of the Related Art
An asphalt has a water-proofing property and an antiseptic property and hence has hitherto been utilized as a road-paving material, a water-proofing material, and the like. For the purpose of improving its adhesiveness, abrasion resistance, impact resistance, low-temperature properties (e.g., low-temperature elongation), and the like, the modification of the asphalt has been effected by adding a latex thereto.
As a latex (an asphalt modifier) for use in such modification of the asphalt, there is known a cationic latex obtained by converting an anionic styrene-butadiene copolymer latex into cationic one (for example, see Japanese Patent Publication Nos. 10615/1973 and 10939/1973) or an anionic latex obtained by dispersing a conjugate dienic copolymer containing an unsaturated carboxylic acid unit in water with an anionic surfactant (for example, see Japanese Patent No. 3336833).
The above cationic latex is excellent in compatibility with an asphalt (usually, being used as a cationized form with a cationic surfactant) or an asphalt emulsion, especially a cationic asphalt emulsion, and the above anionic latex exhibits a strong adhesiveness to an aggregate, so that both of them are suitably used as asphalt modifiers.
However, in recent years, a more efficient high-performance latex (asphalt modifier) having both of the compatibility of the above cationic latex with an asphalt and the strong adhesiveness of the above anionic latex to an aggregate is highly desired.